1. Field of the Invention
The present invention relates to a bumper mounting structure, and more particularly to a bumper mounting structure which improves the impact energy absorbing property of a bumper to thereby minimize possibly injury to a driver and/or a passenger to and to prevent various parts in an engine room from being broken.
2. Description of the Related Art
A bumper is installed to a front end and a rear end of an automobile such that it can absorb an impact force exerted on it upon impact to thereby protect a body of the automobile. While, in the past, a bumper which projects a little from the body was used, more recently a larger bumper, which is called an energy absorbing bumper, has been used in America. Generally, a bumper has a construction in which an energy absorbing material is placed between a steel beam and a cover. Urethane, etc. can be used as the energy absorbing material.
More recently, instead of a bumper having a complicated construction as mentioned above, a back beam which is capable of maintaining a beam rigidity and at the same time absorbing an impact force, is widely used. The back beam for a bumper is manufactured by a blow molding process which is a kind of plastic molding and in which a doubly stacked sheet-shaped molding material or a tubular-shaped molding material is inserted into a mold and then air is blown into them to make a hollow-shaped product. By the blow molding process, a plurality of tack-off portions are formed in the back beam, and a plurality of lobes are defined in the back beam by the plurality of tack-off portions. A bumper cover is secured to the back beam by a retainer. A rib is provided in the back beam to maintain rigidity, and an air inlet is formed in the lower portion of the bumper cover to allow outside air to flow into engine room.
A bumper mounting structure of the prior art includes a bumper stay and a front side member. One end of the bumper stay is integrally fixed to the bumper, and the other end of the bumper stay is rigidly fastened to the front side member by a proper locking means as is known in the art.
However, in the bumper mounting structure of the prior art, constructed as mentioned above, since the bumper stay is rigidly fastened to the front side member, it becomes impossible to absorb impact energy exerted on the bumper upon impact at a connection between the bumper stay and the front side member. Accordingly, because there is a limit in capability of the bumper for absorbing the impact energy, when a low-speed impact occurs, various parts in an engine room are broken and possible injury to a driver and/or a passenger is increased.